Fake reverse NAT for hosting my Ark Survival Evolved Servers at home

• i have named it like this…

the problem

• the Ark Survival Evolved Server runs on a Server in the same LAN on which some clients who want to play are… this LAN is NATed
• joining one Ark server works fine, but when the feature of transferring to another server is used, the client wants to connect to the Public IP of the other Ark server
• most cheap and crappy home routers don’t support connections to their Public IP from within the NATen LAN (which would then be forwarded according to DMZ = Demilitarized Zone or Port Forwarding)

how it works

• some special IPtables rules on a Linux server
  • forward all packets, which would go to the Public IP… directly to the internal Ark server and the rest to the actual Default Gateway of the LAN
  • make return packets work
• this Linux server is configured to be the Default Gateway on all Clients in the LAN wanting to play Ark Survival Evolved
• transferring between servers now works